Logical reasoning PrepTest 146 · Section 2 · Question 12

Correct. Argument or Facts:
Facts

Question Type:
Paradox

Stimulus Summary:
1955 analysis: Cobalt not used in painting before 1804 is present in a painting, so the painting is from after 1804.
2009 analysis: Cobalt is present in the painting, but it was made before 1804.

Answer Anticipation:
This stimulus is all about explaining a paradox with a timeline. Both analyses show cobalt in a painting, and there's no question that cobalt wasn't used in a painting before 1804. However, we need to explain, then, how the painting can be from before 1804—as the second analysis suggested. Remember that we're trying to resolve the paradox, not decide who's right, so we can't just state that the second analysis was wrong. Instead, we have to find a way that a painting could be made before 1804 but end up with paint in it that is from after that date. Anything suggesting that paint was added to the painting for some reason after it was created, therefore, will serve to resolve the paradox.

Answer Explanation:
This answer suggests a reason that paint would be added to the painting after it was initially created. If the cobalt is just in a layer that was applied to fix up damage to the earlier painting, then it's possible for the painting to have been done before 1804 and fixed up after that date.

Key Takeaway:
Making sense of timelines is something that the LSAT tests frequently. It's inherently related to causality (the cause must occur before the effect), but it doesn't only show up in causal argument. Also look for it in questions focused on explaining weird situations or, as we see here, paradoxical ones.

Incorrect. The 2009 analysis found cobalt in the painting, and that paint is still from after 1804, so this answer does nothing to explain why that analysis found apparently contradictory results!

Incorrect. There's no indication that the number or size of samples is related to accuracy, and there's also no indication that the results were inaccurate—especially since they agree on the presence of cobalt!

Incorrect. This answer might highlight that the painting is from before 1804, but it doesn't explain how that cobalt got in it.

Incorrect. This doesn't change that cobalt wasn't used before 1804, and so it's still a paradox that the cobalt paint from after 1804 is in this painting believed to be from before then.